A way to assess individual stability and change, both growth and decay, over time. A two-level, hierarchical model that that models (1) within individual change over time and (2) between individual differences in patterns of growth.
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Why Latent?
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Because we assume that whatever process that is underlying the thing we are modeling (or the behavior we observe) is actually unobserved. This language grew out of structural equation modeling (SEM).
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. or latent. The characteristics we observe are a manifestation of this latent trajectory.

– You may also believe that not everyone follows the same path.Why use GM’s?
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Everyone else is doing it!
– – – – – Education Criminology Psychology Sociology Public Health
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You have longitudinal data and are interested in change over time.
– You may want to explain those changes.
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Forthcoming. resource model). crisis model) or long-term impacts on health (i. American Sociological Review. & Brooks-Gunn. McLanahan.” Meadows.. We wanted to know whether changes in family structure.A Detailed Example
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“Stability and Change in Family Structure and Maternal Health Trajectories.e. had short-term impacts on health (i.
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.e. including transitions into and out of coresidential relationships..

Two measures of family structure change:
– Level 1: Time-Varying – Level 2: Time-Invariant
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.)
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Trajectories of maternal self-rated health and mental health problems from one year after birth to five years after birth.Example (cont.

resulted in short-term declines in physical health and short-term increases in mental health problems.Example (cont. as well as mothers who made transitions. – Little support for the resource model. especially exits from marriages.)
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Results:
– Transitions.
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. no growing gap in well-being between mothers who remained stably married and those remained stably single.

Mixture Models
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Latent Class Models (LCM/LCA)
– Group membership not known.
Latent Class Growth Models (LCGM/LCGA)
– Group membership not known and is based on trajectory patterns.
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.
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Growth Mixture Models (GMM)
– Group membership is not known and is based on trajectory patterns. – No variation is allowed within latent classes. – Allows for variation within latent classes.